Method for controlling color on printing machines

Abstract

A method for color correction in printing machines uses a learning process to determine the effects of changing colors. In a first stage of the method, the color supply of only a single process color is changed. The effect of changing the color supply of this one process color on the color values of a color spot to be measured is determined, and a corresponding chromaticity position is stored as a measurement value or measurement value set for this color. This-process can be performed separately one after the other for each individual process color involved in the autotype combination printing. In a second stage, all of the measurement values determined and stored earlier for all of the involved process colors are balanced with each other, such that for further color correction, a few or all of the process colors involved in the printing can be adjusted simultaneously.

1 - 7 . (canceled)  
     
     
         8 . A method for color correction in printing machines, comprising: 
 (a) executing separately one after the other for individual process colors involved in an autotype combination printing; changing only the color supply of a single process color; determining the effect of the change in the color supply of this one process color on color values of a color spot to be measured; and storing a corresponding color spot for this color;    (b) balancing all of the measurement values determined and stored in step (a) with each other so that for further color correction, a few or all of the process colors involved in the printing can be adjusted simultaneously.    
     
     
         9 . A method according to  claim 8 , wherein during the printing at least one color spot is measured, wherein for this measurement at least one actual chromaticity position is determined, and that the actual chromaticity position or each actual chromaticity position is compared with a corresponding desired chromaticity position, wherein the color correction is performed when the actual chromaticity position deviates from the corresponding desired chromaticity position.  
     
     
         10 .  3 . A method according to  claim 8 , wherein for determining the measurement values of the chromaticity position or each chromaticity position, control waits in step a) until a balanced state has been reached after a color supply of the corresponding color to be printed has been changed.  
     
     
         11 . A method according to  claim 8 , wherein for determining the measurement values of the chromaticity position or each chromaticity position in step a), at least one value is measured after a certain time period or at certain time intervals and control locks the changing balanced state through extrapolation.  
     
     
         12 . A method according to one or more of  claim 8 , wherein in step (a), for each process color to be printed, the effect of the isolated change in a color supply of each process color on the chromaticity position of the color spot to be measured, is measured separately one after the other in time.  
     
     
         13 . A method according to  claim 12 , wherein it is determined how the corresponding chromaticity position shifts when changing the color supply of each process color, and that the magnitude and direction of a color vector are determined from the chromaticity positions before the color change and after the color change.  
     
     
         14 . A method according to one or more of claims  1 , characterized in that the determined and stored measurement values according to step (b) are balanced through vector operations.